This invention relates to a driving apparatus for electric power circuit breakers having power accumulator springs which engage a shaft by means of a crank arm and can be latched in the cocked condition.
A driving apparatus of this kind is described, for instance, in the German Offenlegungsschrift No. 22 36 788. In general, the following switching operations are required of such driving apparatus: immediate closing by means of a closing command at the breaker itself or by remote control in a control room; immediate opening, likewise by a switching command given at the breaker or in a control room; and automatic closing and opening in dependence on protective or safety devices.
Because short interruption is frequently required, the driving apparatus must also be able to reclose the circuit immediately after an interruption and, then, to interrupt it again in case the short interruption did not correct the fault.
The driving energy for these switching actions are stored in springs which can be cocked by a cocking device such as a motor drive. If the driving apparatus is designed so that the energy required for opening the breaker is supplied by the closing springs and transferred to the opening springs during the closing process, then stringent requirements as to energy limits and mechanical reliability are placed on that part of the driving apparatus which contains the closing springs. The larger the electrical switching capacity needed in the power circuit breakers, the harder these requirements are to meet. In particular, the vibrations emanating from the driving apparatus become a considerable problem in the entire breaker since this not only stresses all parts mechanically to a considerable degree, but also can impair the functioning of the more sensitive parts of the power circuit breaker, such as auxiliary switches, relays, contactors, tripping devices and the like.